code: def test_indexed_join(how):
      p_left = pd.DataFrame(
          {"x": np.arange(10)}, index=np.arange(10) * 2
      )
      p_right = pd.DataFrame({"y": 1}, index=np.arange(15))
  
      g_left = cudf.from_pandas(p_left)
      g_right = cudf.from_pandas(p_right)
  
      dg_left = dd.from_pandas(g_left, npartitions=4)
      dg_right = dd.from_pandas(g_right, npartitions=5)
  
      d = g_left.merge(
          g_right, left_index=True, right_index=True, how=how
      )
      dg = dg_left.merge(
          dg_right, left_index=True, right_index=True, how=how
      )
  
      # occasionally order is not correct (possibly do to hashing in the merge)
      d = d.sort_values("x")  # index is preserved
      dg = dg.sort_values(
          "x"
      )  # index is reset -- sort_values will slow test down
  
      dd.assert_eq(d, dg, check_index=False)
  
file_path: cudf/python/dask_cudf/dask_cudf/tests/test_join.py
imports: from functools import partial
  import numpy
  import pandas
  import pytest
  from dask import dataframe
  import cudf
  import dask_cudf
label_desc: Use image node_id 6 for calling a global function with example usage: test_indexed_join(how) without return types